The famous Ring Nebula (also catalogued as Messier 57, M57 or NGC 6720) appears in the northern constellation of Lyra. It is a prominent example of a planetary nebula. This is a shell of ionized gas expelled into the surrounding interstellar medium by a red giant star, which was passing through the last stage in its evolution before becoming a white dwarf.
Read more about Ring Nebula: History, Observation, Properties
Famous quotes containing the word ring:
“These words dropped into my childish mind as if you should accidentally drop a ring into a deep well. I did not think of them much at the time, but there came a day in my life when the ring was fished up out of the well, good as new.”
—Harriet Beecher Stowe (1811–1896)